The Process-observational and extremal characteristics Analysis of the European Record-Breaking Heatwave in 2022 Summer

Europe had experienced anomalously heatwave that significantly deviated from climatic norms in 2022 summer (June and July). Researches on this extreme event can enhance China"s global forecasting capabilities in regional extreme high-temperature weather.By Using multi-source observations in Central and Western Europe, this arctile analyzes the traits of the process-observations and extremal characteritics of such widespread and persistent heat wave. The results show as follows: 1) This heatwave event (defined as daily maximum temperature≥32℃ for 3 consecutive days) affected central and western Europe, and lasted for approximately?59 days. The number of days, with daily highest temperature exceeding 40℃, in France, Spain, Portugal and other countries reached 7-15. The highest recorded daily temperature during the whole heatwave was 47℃ in Pinh?o(in Portugal, not a Global Transition Station),,while the United Kingdom observed a daily maximum temperature above 40℃ for the first time in its history. The whole heat wave was composed of four consecutive sub-processes, and the intensity of the high temperature in the fourth sub-process (July 17th - 29th) scaled the peak.2) Compared to the three typical heatwave events since the 21st century, those occurred in the year of 2003 (affecting Western Central and Southern Europe, lasting 31 days ,with a peak daily temperature of 45.2℃), 2013 (affecting northern Western Europe, lasting 19 days,with a peak daily temperature of 38.1℃), and 2019 (affecting Western and Central Europe, lasting 8 days,with a peak daily temperature of 42.6℃), the heatwave in 2022 had exhibited the highest intensity, longest duration, and broadest spatial impact in recorded history.3)The ECA&D stations gave the highest daily temperature observations, the GTS stations showed the best(shortest) monitoring timeliness, the GSOD stations yielded the highest accuracy in reflecting extreme historical records, while the ERA5’s extreme high temperature values are relatively weak.